Prior art metal housings for optical transceivers have been cast, molded, formed, or machined from a variety of alloys, such as an aluminum alloy. Some metal mounting posts were press inserted or threaded into holes in the housings. Other metal housings had mounting posts that were integrally machined or cast oversized and machined in a secondary operation. It has been found during wave soldering of electrical leads and the mounting posts to traces on a substrate, that the metal housing acts as a large heat sink with respect to the mounting posts. This has caused cold solder joints to form at some mounting posts. The cold solder joints decrease the reliability of a circuit path from the housing to an electrically conductive trace on the substrate on which the housing is mounted, and reduce the retention force of the solder joints that secure the housing to the substrate. Concomitantly, a failed solder joint will reduce the shielding effectiveness of the housing by including a high impedance in the path between the conductive housing and an electrically conductive trace on the substrate.
Prior art plastic housings for optical transceivers have included insert molded, ultrasonically bonded, or threaded, screw inserted metal mounting posts. The ultrasonically bonded mounting posts were typically plated, along with the housing, after insertion. The threaded screw inserted mounting posts were typically mounted into the housing after both the housing and the mounting posts were individually plated. Inserting the mounting post subsequent to both the housing and mounting posts being individually plated has caused the plating to crack.
The above problems, coupled with tolerance requirements on the positioning of the mounting posts, requires that each housing be inspected after manufacture. This increases the cost of manufacturing housings for optical transceivers. A need remains in the art for a cost effective technique for providing shielding to a housing while simultaneously providing a reliable low impedance path to conduct electrostatic energy or energy induced by electromagnetic radiation to an electrically conductive trace.